Traditional fluid supply device usually assembles filter for promoting the cleanness of the output fluid, i.e. filter of the drinking water supply machine, automatic drinking fluid supply machine, industrial air compressor or hydraulics system also assembles filter, but, by slow accumulation, and for a long time, the dirts on filter must be cleaned, if user neglects it to cause blockade or pollute the fluid, the present invention can provide structure of automatic periodically positive and reverse flow cleaning cycle to improve the above defect.